Invasive candidiasis in the ICU — recognition, investigation and empiric therapy

Diagnosis: candidaemia with septic physiology, in a high-risk ICU patient. The yeast-positive blood cultures confirm invasive candidiasis; the risk profile — central line, prolonged ICU stay, broad-spectrum antibiotics, total parenteral nutrition, and recent abdominal surgery with GI perforation — is textbook (mnemonic CANDIDA).^[1][3]

Immediate assessment — ABCDE + Surviving Sepsis hour-1 bundle.

• Airway / Breathing — oxygen to target SpO2 94–98%; assess work of breathing.
• Circulation — two reliable IV lines (NEW peripheral access if the central line is to be removed); balanced crystalloid 30 mL/kg for hypotension and lactate 2.6 mmol/L; noradrenaline if fluid-refractory.
• Cultures and biomarkers — blood cultures already positive (yeast); send two fresh peripheral sets plus a set through each lumen of the central line; serum (1→3)-beta-D-glucan; T2Candida / PCR if available; lactate, FBC, CRP, U&E, LFTs, urine output (catheterise).

Empirical antifungal within the first hour — an echinocandin (IDSA 2016 first-line).^[3]

• Caspofungin 70 mg IV loading dose, then 50 mg IV once daily (increase to 70 mg/day if body weight more than 80 kg), OR
• Micafungin 100 mg IV once daily, OR
• Anidulafungin 200 mg IV loading dose, then 100 mg IV once daily.

The choice of echinocandin (rather than fluconazole) reflects the rising prevalence of fluconazole-resistant non-albicans species in ICU patients and the higher mortality of inadequate initial therapy.

Source control — remove the central venous catheter within 24 hours if feasible; send the tip for semi-quantitative culture. Address any intra-abdominal collection (drainage).^[3]

Look for metastatic foci:

• Ophthalmology dilated fundoscopy within the first week — endophthalmitis is found in up to a quarter of candidaemia patients and changes the duration and route of therapy.
• Echocardiography — if persistent fever/bacteraemia, prosthetic valve, or suspicion of endocarditis.
• CT abdomen — for hepatosplenic / intra-abdominal abscess.

Step-down and duration (once cultures speciate and susceptibility returns):

• If isolate is fluconazole-susceptible (e.g. C. albicans, C. parapsilosis, C. tropicalis) AND the patient is clinically stable with repeat cultures negative → step down to oral fluconazole 400 mg/day.
• If C. glabrata / C. krusei → continue echinocandin (or voriconazole step-down for C. krusei, which is intrinsically fluconazole-resistant).^[3]
• Total duration: 2 weeks AFTER THE FIRST NEGATIVE blood culture, provided source control is achieved and there is no metastatic focus (no endophthalmitis, endocarditis, hepatosplenic disease).^[3]